Increased production of nitric oxide in patients infected with the European variant of hantavirus.

Serum nitrate levels, a measure of nitric oxide (NO) production in vivo, were very high (95 +/- 14 microM) in 13 patients infected with Puumala virus, the European variant of Hantavirus (HTV), as compared to those in healthy subjects (33 +/- 3 microM). Serum nitrate levels showed a high and significant correlation with scores on the Acute Physiological And Chronic Health Evaluation (APACHE II) scale and with serum creatinine, and an inverse correlation with platelet counts. Serial serum measurements of nitrate in 2 severe cases showed very high levels at the onset of arterial hypotension and acute renal failure. We conclude that excessive amounts of NO are produced in patients infected with Puumala virus and that this reactive nitrogen intermediate could play an important role in the pathogenesis of the disease.